Intraoral elastics, sometimes referred to as orthodontic "elastic bands," have been used in the orthodontic profession for many years. The term "intraoral elastic bands," as used herein and as commonly understood, refers to elastic bands which are replaceably placed in tension between securement points, usually hooks, in the mouth. Such elastic bands are replaced by the patient frequently, preferably several times each day.
Intraoral elastic bands are usually in the form of endless loops, but this invention may apply to other forms of elastic bands in which strands are replaceably placed in tension between hooks in the mouth. In the typical endless loop form, various strengths and sizes of loops are used depending on the geometry of the orthodontic need, that is, the distance between hooks, and other factors.
Intraoral elastic bands, which are stretched between hooks secured to the teeth, apply directional force to the teeth. The elastic force of the intraoral elastic bands is applied in manner urging teeth to move from their positions of malocclusion to their non-orthodontic normal positions. Moving teeth is the sole purpose of orthodontic elastic bands.
Frequent replacement of intraoral elastic bands by the patient is essential to maintaining the intended level of corrective force on an improperly located tooth. This is due to the fact that the elastic strength of intraoral elastic bands decays rapidly in the oral environment.
The weakening of the elastic force of intraoral elastic bands occurs as water and acids in the mouth are absorbed into the elastic band. Weakening begins upon first exposure within the oral environment and continues. When the liquids in the mouth are absorbed throughout the elastic band, its elastic strength is at a much lower level than during the period immediately after placement in the mouth.
More specifically, the elastic modulus of certain common orthodontic elastic bands typically decays about 40-60 percent during the first two hours after placement in tension in the mouth of the patient. The corrective force applied by such elastic band is thus substantially reduced over this short initial period of use.
Many patients, however, do not replace their orthodontic elastic bands until hours after the loss of most of their elastic strength. Therefore, the corrective pressure applied on the teeth of such patients, by a series of elastic bands, is applied with substantial variation and with extended interruptions.
Infrequent and irregular replacement of intraoral elastic bands is a common problem in the field of orthodontics. This can greatly extend the length of the period of orthodontic care for the patient. In many cases, the period of orthodontic treatment extends for months beyond what would otherwise be necessary.
Improving regularity and faithfulness of elastic band replacement is very helpful in orthodontic treatment. Even more important is increasing the frequency of a patient's elastic band replacement.
Many patients replace their orthodontic elastic bands at specific times of the day, for example, upon rising in the morning and retiring at night, or upon the occurrence of other regular events, such as meals. Others are less faithful. However, even following a fairly rigorous schedule of changes, three or four times daily, the amount of corrective force applied to the teeth is insufficient over long periods and varies too much. More frequent replacement would be desirable.
Few patients are willing or able to remember to change orthodontic elastic bands frequently enough for the most effective application of corrective force. Children may be very lax in making required changes on time. They usually consider anything having to do with their orthodontic treatment to be a negative experience, so are often quite willing to forget or postpone the replacement of their orthodontic elastic bands.
Orthodontic elastic bands are not a particularly appealing thing to place in one's own mouth. And, there is nothing about the act of replacing orthodontic elastic bands which makes it a pleasant experience, or in any sense a rewarding experience.
Efforts to increase the frequency of elastic band replacement and/or at least to encourage compliance with some sort of schedule have not been particularly successful. So the typical course of orthodontic treatment for a patient has remained longer than is necessary.